Ants
Harvester ants (Pogonomyrmex spp.) and fire ants (Solenopsis spp.) can cause
allergic reactions in the Southwest, especially in children. Harvester ants build
"volcano" cones of tiny pebbles at the nest entrance. Several species of
native fire ants are indigenous to the region. The imported fire ant, which builds
very large mounds over their nests, has been extending its range westward, but aside from
a single colony, has not yet reached Arizona in significant numbers. Patients
allergic to the imported fire ant may also be allergic to the native species.
Photo
courtesy of Hayward Spangler PhD
Yellow harvester ant (P. maricopa) - similar to the
red harvester ant
P. californicus) and measures 7-8 mm. Fire ants are half this size.